In some women, morning sickness might be an indicator of more serious later-pregnancy complications, including preterm delivery, a new study says.
In the study, women who reported nausea and vomiting in pregnancy that interfered with their ability to live normally were 23 percent more likely to deliver their baby before 34 weeks, and 31 percent more likely to have high blood pressure or preeclampsia, compared with women who said their morning sickness did not substantially affected their lives.
Women with life-affecting morning sickness were also about twice as likely to have low weight gain during pregnancy.
The findings underscore the importance of recognizing morning sickness and managing it, said study researcher Dr. Gary Stanziano, of Alere Health, a company that produces health care products and offers a program to treat morning sickness.
"This should not be a condition that’s taken lightly," Stanziano said.
Severe morning sickness
About 50 to 60 percent of pregnant women experience some type of morning sickness during pregnancy, Stanziano said. About 1 percent have a severe, persistent form known as hyperemesis gravidarum, which can lead to malnutrition.
While the immediate effects on mothers are easy to observe, few studies have investigated the impact of nausea and vomiting on the later stages of pregnancy, and delivery.
Stanziano and colleagues analyzed information from 81,486 women enrolled in an Alere maternity education program who delivered between 2004 and 2011. After delivery, the women were asked whether they had experienced nausea and vomiting during their pregnancy that affected their ability to do their job or their daily activities. About 5,200 women, or 6.4 percent of those surveyed, reported nausea and vomiting that affected their quality of life. About 1,800 women of these said they did not require any interventions, while about 3,300 required hydration or pharmacological treatments.
Of those who said the nausea and vomiting affected their quality of life, 23 percent had low weight gain for their pregnancy, compared with13.7 percent of women who did not have such sickness.
In addition, about 10 percent of those who got sick had infants who were small for their gestational age when they were born, compared with 8.4 percent of those who didn't have nausea and vomiting.
Researchers aren't sure why women with severe morning sickness saw these effects. But poor nutrition and too little weight gain in pregnancy may contribute to the risk, Stanziano said.
Indeed, it's hard to tell whether the effects seen in the study were due to nausea and vomiting, or to the low weight gain these women experienced, saidDr. Jennifer Wu, an obstetrician and gynecologist at Lenox Hill Hospital in New York City, who was not involved in the study. Poor weight gain has previously been shown to be associated with preterm delivery and babies born small for their gestational age, Wu said.
Fortunately, only a small number of pregnant women experience significant nausea and vomiting that lasts beyond 10 to 16 weeks of pregnancy, Wu said.
Women who do have such symptoms should discuss them with their doctors, who may be able to provide solutions, Wu said.
While no drugs for pregnancy nausea and vomiting have been approved by the Food and Drug Administration, many excellent therapies exist, Stanziano said. These include hydration and nutrition supplements, as well as some medications used off label, Stanziano said.
A change of diet, such as eating six to seven small meals a day rather than three large meals, may also help, Wu said.
The findings were presented last week at the Society for Maternal-Fetal Medicine's annual meeting in Dallas. Study data was provided by Alere and analyzed by researchers at Carolinas Medical Center, with no additional funding from either organization.
Pass it on: Some forms of nausea and vomiting in pregnancy can increase the risk of adverse pregnancy outcomes, and women should speak with their doctor about symptoms.
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Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.